Name: a model of long-term ventricular fibrillation in isolated rat hearts
Uploaded: 2023-02-17T14:15:00
Description: Watch this Scientific Journal Video about A Model of Long-Term Ventricular Fibrillation in Isolated Rat Hearts at JoVE.com

Bu çalışma Kardiyovasküler Cerrahi, İlk Tıp Merkezi, Çin PLA Genel Hastanesi ve Laboratuvar Hayvanları Merkezi, Çin PLA Genel Hastanesi'nin desteğiyle gerçekleştirilmiştir.

Bu araştırmada kullanılan tüm deneysel prosedürler ve protokoller PLA Genel Hastanesi Hayvan Bakımı ve Kullanımı Komitesi tarafından gözden geçirilmiş ve onaylanmıştır.
1. Langendorff aparatının hazırlanması
<ol><li>Krebs-Henseleit (K-H) arabelleğini hazırlayın. K-H tamponunu hazırlamak için damıtılmış suya aşağıdakileri ekleyin: 118,0 mM NaCl, 4,7 mM KCl, 1,2 mM MgSO 4, 1,2 mM NaH 2 PO4, 1,8 mM CaCl 2,</s...

<ol>
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J., Kampman, K., Glagov, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ventricular+fibrillation+during+cardiopulmonary+bypass:+Long-term+effects+on+myocardial+morphology+and+function.">Ventricular fibrillation during cardiopulmonary bypass: Long-term effects on myocardial morphology and function.</a> The Annals of Thoracic Surgery. 27 (3), 230-234 (1979).</li><li>Li, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pravastatin+attenuates+cardiac+dysfunction+induced+by+lysophosphatidylcholine+in+isolated+rat+hearts.">Pravastatin attenuates cardiac dysfunction induced by lysophosphatidylcholine in isolated rat hearts.</a> European Journal of Pharmacology. 640 (1-3), 139-142 (2010).</li><li>Lang, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CXCL10/IP-10+neutralization+can+ameliorate+lipopolysaccharide-induced+acute+respiratory+distress+syndrome+in+rats.">CXCL10/IP-10 neutralization can ameliorate lipopolysaccharide-induced acute respiratory distress syndrome in rats.</a> PLoS One. 12 (1), e0169100 (2017).</li><li>Lubbe, W. F., Bricknell, O. L., Marzagao, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ventricular+fibrillation+threshold+and+vulnerable+period+in+the+isolated+perfused+rat+heart.">Ventricular fibrillation threshold and vulnerable period in the isolated perfused rat heart.</a> Cardiovascular Research. 9 (5), 613-620 (1975).</li><li>Hottentrott, C. E., Towers, B., Kurkji, H. J., Maloney, J. V., Buckberg, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+hazard+of+ventricular+fibrillation+in+hypertrophied+ventricles+during+cardiopulmonary+bypass.">The hazard of ventricular fibrillation in hypertrophied ventricles during cardiopulmonary bypass.</a> The Journal of Thoracic and Cardiovascular Surgery. 66 (5), 742-753 (1973).</li><li>Hottenrott, C., Maloney, J. V., Buckberg, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+of+the+effects+of+ventricular+fibrillation+on+the+adequacy+of+regional+myocardial+flow.+I.+Electrical+vs.+spontaneous+fibrillation.">Studies of the effects of ventricular fibrillation on the adequacy of regional myocardial flow. I. Electrical vs. spontaneous fibrillation.</a> The Journal of Thoracic and Cardiovascular Surgery. 68 (4), 615-625 (1974).</li><li>Buckberg, G. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+of+the+effects+of+hypothermia+on+regional+myocardial+blood+flow+and+metabolism+during+cardiopulmonary+bypass.+I.+The+adequately+perfused+beating,+fibrillating,+and+arrested+heart.">Studies of the effects of hypothermia on regional myocardial blood flow and metabolism during cardiopulmonary bypass. I. The adequately perfused beating, fibrillating, and arrested heart.</a> The Journal of Thoracic and Cardiovascular Surgery. 73 (1), 87-94 (1977).</li><li>Gazmuri, R. J., Berkowitz, M., Cajigas, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myocardial+effects+of+ventricular+fibrillation+in+the+isolated+rat+heart.">Myocardial effects of ventricular fibrillation in the isolated rat heart.</a> Critical Care Medicine. 27 (8), 1542-1550 (1999).</li><li>Clasen, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+modified+approach+for+programmed+electrical+stimulation+in+mice:+Inducibility+of+ventricular+arrhythmias.">A modified approach for programmed electrical stimulation in mice: Inducibility of ventricular arrhythmias.</a> PLoS One. 13 (8), e0201910 (2018).</li><li>Diaz-Maue, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advanced+cardiac+rhythm+management+by+applying+optogenetic+multi-site+photostimulation+in+murine+hearts.">Advanced cardiac rhythm management by applying optogenetic multi-site photostimulation in murine hearts.</a> Journal of Visualized Experiments. (174), e62335 (2021).</li><li>Jungen, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+intracardiac+neurons+on+cardiac+electrophysiology+and+arrhythmogenesis+in+an+ex+vivo+Langendorff+system.">Impact of intracardiac neurons on cardiac electrophysiology and arrhythmogenesis in an ex vivo Langendorff system.</a> Journal of Visualized Experiments. 135, e57617 (2018).</li><li>Koretsune, Y., Marban, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+calcium+in+the+pathophysiology+of+ventricular+fibrillation+and+in+the+pathogenesis+of+postarrhythmic+contractile+dysfunction.">Cell calcium in the pathophysiology of ventricular fibrillation and in the pathogenesis of postarrhythmic contractile dysfunction.</a> Circulation. 80 (2), 369-379 (1989).</li><li>Brazier, J. R., Cooper, N., McConnell, D. H., Buckberg, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+of+the+effects+of+hypothermia+on+regional+myocardial+blood+flow+and+metabolism+during+cardiopulmonary+bypass.+III.+Effects+of+temperature,+time,+and+perfusion+pressure+in+fibrillating+hearts.">Studies of the effects of hypothermia on regional myocardial blood flow and metabolism during cardiopulmonary bypass. III. Effects of temperature, time, and perfusion pressure in fibrillating hearts.</a> The Journal of Thoracic and Cardiovascular Surgery. 73 (1), 102-109 (1977).</li><li>von Planta, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiopulmonary+resuscitation+in+the+rat.">Cardiopulmonary resuscitation in the rat.</a> Journal of Applied Physiology. 65 (6), 2641-2647 (1988).</li><li>Luo, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ageing+increases+cardiac+electrical+remodelling+in+rats+and+mice+via+NOX4/ROS/CaMKII-mediated+calcium+signalling.">Ageing increases cardiac electrical remodelling in rats and mice via NOX4/ROS/CaMKII-mediated calcium signalling.</a> Oxidative Medicine and Cellular Longevity. 2022, 8538296 (2022).</li><li>Hohnloser, S., Weirich, J., Antoni, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+direct+current+on+the+electrical+activity+of+the+heart+and+on+its+susceptibility+to+ventricular+fibrillation.">Influence of direct current on the electrical activity of the heart and on its susceptibility to ventricular fibrillation.</a> Basic Research in Cardiology. 77 (3), 237-249 (1982).</li><li>Xie, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-energy+defibrillation+increases+the+severity+of+postresuscitation+myocardial+dysfunction.">High-energy defibrillation increases the severity of postresuscitation myocardial dysfunction.</a> Circulation. 96 (2), 683-688 (1997).</li><li>Manoach, M., Netz, H., Erez, M., Weinstock, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ventricular+self-defibrillation+in+mammals:+Age+and+drug+dependence.">Ventricular self-defibrillation in mammals: Age and drug dependence.</a> Age and Ageing. 9 (2), 112-116 (1980).</li><li>Filippi, S., Gizzi, A., Cherubini, C., Luther, S., Fenton, F. 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Bu protokol, daha önce bildirilmemiş olan izole sıçan kalplerinde uzun süreli VF'nin bir hayvan modelini oluşturur. Ayrıca bu çalışmada farklı elektriksel stimülasyon koşulları karşılaştırılmıştır. Bu çalışma, kalp cerrahisi sırasında ventriküler fibrilasyon durması ile ilgili çalışmalar için bir model sunmaktadır.
Modelin başarı oranı, personel, zaman ve ekonomik maliyetlerle ilgili çok önemli bir göstergedir. VF modellerinde başarı oranı, VF'nin kal...

Kalp cerrahisi genellikle torakotomi yoluyla, aortun bloke edilmesi ve kalbi tutuklamak için kardiyoplejik bir solüsyonla perfüzyon ile gerçekleştirilir. Tekrarlayan kalp cerrahisi ilk ameliyattan daha zor olabilir, komplikasyon ve mortalite oranları daha yüksektir 1,2,3. Ayrıca, konvansiyonel medyan sternotomi yaklaşımı, sternumun arkasındaki köprü damarlarına, yükselen aorta, sağ ventriküle ve diğer önemli yapılara zarar verebilir. Bağ dokusunun ayrılmasına bağlı yaygın kanama, sternal yara enfeksiyonu ve sternotomiye bağlı sternal osteomiyelit olası komplikasyonlardır. Kapsamlı diseksiyon vital kardiyak yapılarda lezyon ve kanama riskini arttırır.
Minimal invaziv kalp cerrahisinin gelişmesiyle birlikte, insizyonlar küçülmüştür ve kalp durması bazen zordur. Ventriküler fibrilasyon (VF)4,5 altında tekrarlanan kalp cerrahisi güvenli, uygulanabilir ve daha iyi miyokard koruması sağlayabilir. Bu nedenle, bu protokol minimal invaziv ekstrakorporeal dolaşım ile cerrahide VF kardiyak arrest yöntemini tanıtmaktadır. Kalp, VF sırasında etkili kasılmayı kaybeder ve bu nedenle, ameliyat sırasında artan aortu dikmeye ve bloke etmeye gerek yoktur, bu da prosedürü basitleştirir. Bununla birlikte, kalp sürekli perfüze edilse bile, uzun süreli VF hala kalbe zararlı olabilir.
Bu yöntem daha yaygın olarak kullanılmaya başlandıkça, VF sırasında kalbin nasıl korunacağı sorusu giderek daha fazla önem kazanmaktadır. Bu, uzun vadeli VF'nin hayvan modellerini kullanarak kapsamlı ve derinlemesine çalışmalar gerektirecektir. Geçmişte, bu alandaki araştırmalar çoğunlukla büyük hayvanlar6,7 kullanmış ve cerrahlar, anestezistler, perfüzyonistler ve diğer araştırmacılar arasında işbirliği gerektirmiştir. Bu çalışmalar çok uzun sürdü, örneklem büyüklükleri genellikle küçüktü ve çalışmalar genellikle kardiyak fonksiyona odaklandı ve mekanik ve moleküler değerlendirmelere daha az odaklandı. Bugüne kadar, hiçbir çalışma uzun vadeli bir VF modeli oluşturmak için ayrıntılı bir protokol bildirmemiştir.
Bu protokol, Langendorff aparatını kullanarak uzun vadeli bir VF sıçan modeli geliştirmek için gereken ayrıntıları sağlar. Protokol basit, ekonomik, tekrarlanabilir ve kararlıdır.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0 Non-absorbable suture</td>
			<td>Ethicon, Inc.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>95% O2 + 5% CO2</td>
			<td>Beijing BeiYang United Gas Co., Ltd.&#160;</td>
			<td></td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>AcqKnowledge software</td>
			<td>BIOPAC Systems Inc.</td>
			<td>Version 4.2.1</td>
			<td>Software</td>
		</tr>
		<tr>
			<td>Automatic biochemistry analyzer</td>
			<td>Rayto Life and Analytical Sciences Co., Ltd.</td>
			<td>Chemray 800</td>
			<td>CK-MB assay</td>
		</tr>
		<tr>
			<td>BIOPAC research systems</td>
			<td>BIOPAC Systems Inc.</td>
			<td>MP150</td>
			<td>Hardware</td>
		</tr>
		<tr>
			<td>Blunt needle (20 G, TWLB)</td>
			<td>Tianjin Hanaco MEDICAL Co., Ltd.</td>
			<td>H-113AP-S</td>
			<td>Modified Langendorff perfusion system</td>
		</tr>
		<tr>
			<td>Calcium chloride</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10005861</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>CK-MB assay kits&#160;</td>
			<td>Changchun Huili Biotech Co., Ltd.</td>
			<td>C060</td>
			<td>CK-MB assay</td>
		</tr>
		<tr>
			<td>Curved forcep</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10009717</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Electrical stimulator</td>
			<td>BIOPAC Systems Inc.</td>
			<td>STEMISOC</td>
			<td>Hardware</td>
		</tr>
		<tr>
			<td>Filter</td>
			<td>Tianjin Hanaco MEDICAL Co., Ltd.</td>
			<td>H-113AP-S</td>
			<td></td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>63005518</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Heparin sodium</td>
			<td>Tianjin Biochem Pharmaceutical Co., Ltd.</td>
			<td>H120200505</td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>RWD Life Science Co.,LTD</td>
			<td>21082201</td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Magnesium sulfate</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>20025118</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Needle electrodes</td>
			<td>BIOPAC Systems Inc.</td>
			<td>EL452</td>
			<td>Hardware</td>
		</tr>
		<tr>
			<td>Ophthalmic clamp</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Ophthalmic forceps</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Ophthalmic scissors</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Perfusion tube</td>
			<td>Tianjin Hanaco MEDICAL Co., Ltd.</td>
			<td>H-113AP-S</td>
			<td>Modified Langendorff perfusion system</td>
		</tr>
		<tr>
			<td>Potassium chloride</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10016318</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Sodium bicarbonate</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10018960</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10019318</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Sodium dihydrogen phosphate dihydrate</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>20040718</td>
			<td>K-H buffer</td>
		</tr>
		<tr>
			<td>Sprague-Dawley (SD) rats</td>
			<td>SPF (Beijing) biotechnology Co., Ltd.</td>
			<td>Male, 300-350g</td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Thermometer</td>
			<td>Jiangsu Jingchuang Electronics Co., Ltd.</td>
			<td>GSP-6</td>
			<td>Modified Langendorff perfusion system</td>
		</tr>
		<tr>
			<td>Tissueforceps</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Tissue scissors</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Toothed forceps</td>
			<td>Shanghai Medical Instrument (Group) Co., Ltd.</td>
			<td></td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Ventilator</td>
			<td>Chengdu Instrument Factory</td>
			<td>DKX-150</td>
			<td>Preparation of the isolated heart</td>
		</tr>
		<tr>
			<td>Water bath1</td>
			<td>Ningbo Scientz Biotechnology Co.,Ltd.</td>
			<td>SC-15</td>
			<td>Modified Langendorff perfusion system</td>
		</tr>
		<tr>
			<td>Water bath2</td>
			<td>Shanghai Yiheng Technology Instrument Co., Ltd.</td>
			<td>DK-8D</td>
			<td>Modified Langendorff perfusion system</td>
		</tr>
	</tbody>
</table>

a model of long-term ventricular fibrillation in isolated rat hearts

Ventriküler fibrilasyon (VF) kalp hastalarında görülme sıklığı yüksek olan ölümcül bir aritmidir, ancak perfüzyon altında VF arresti kalp cerrahisi alanında ihmal edilen bir intraoperatif arrest yöntemidir. Kalp cerrahisindeki son gelişmelerle birlikte, perfüzyon altında uzun süreli VF çalışmalarına olan talep artmıştır. Bununla birlikte, alan kronik ventriküler fibrilasyonun basit, güvenilir ve tekrarlanabilir hayvan modellerinden yoksundur. Bu protokol, epikardın alternatif akım (AC) elektriksel stimülasyonu yoluyla uzun süreli VF'yi indükler. VF'yi indüklemek için, uzun süreli VF'yi indüklemek için düşük veya yüksek voltajla sürekli stimülasyon ve spontan uzun süreli VF'yi indüklemek için düşük veya yüksek voltajla 5 dakika boyunca stimülasyon dahil olmak üzere farklı koşullar kullanılmıştır. Farklı durumların başarı oranlarının yanı sıra miyokard yaralanması ve kardiyak fonksiyonların iyileşme oranları karşılaştırıldı. Sonuçlar, sürekli düşük voltajlı stimülasyonun uzun süreli VF'yi indüklediğini ve 5 dakikalık düşük voltajlı stimülasyonun hafif miyokard hasarı ve yüksek oranda kardiyak fonksiyon iyileşmesi ile spontan uzun süreli VF'yi indüklediğini göstermiştir. Bununla birlikte, düşük voltajlı, sürekli uyarılan uzun vadeli VF modeli daha yüksek bir başarı oranına sahipti. Yüksek voltajlı stimülasyon daha yüksek VF indüksiyon oranı sağladı, ancak düşük defibrilasyon başarı oranı, kardiyak fonksiyonun zayıf iyileşmesi ve ciddi miyokard hasarı gösterdi. Bu sonuçlara dayanarak, yüksek başarı oranı, stabilitesi, güvenilirliği, tekrarlanabilirliği, kardiyak fonksiyon üzerindeki düşük etkisi ve hafif miyokard hasarı nedeniyle sürekli düşük voltajlı epikardiyal AC stimülasyonu önerilmektedir.

Deneylerde toplam 57 sıçan kullanıldı ve bunların 30'u dahil etme kriterlerini karşıladı. Dahil edilen hayvanlar, her grupta altı hayvan olmak üzere beş gruba ayrıldı: kontrol grubu (Grup C), düşük voltajlı sürekli uyarılmış uzun süreli VF grubu (Grup LC), yüksek voltajlı sürekli uyarılmış uzun süreli VF grubu (Grup HC), düşük voltaja bağlı spontan uzun süreli VF grubu (Grup LI) ve yüksek voltaja bağlı spontan uzun vadeli VF grubu (Grup HI). Her grup için deneysel süreç <strong cl...

Watch this Scientific Journal Video about A Model of Long-Term Ventricular Fibrillation in Isolated Rat Hearts at JoVE.com

A Model of Long-Term Ventricular Fibrillation in Isolated Rat Hearts

Bu protokol, düşük voltajlı alternatif akımla sürekli stimülasyonla indüklenen sıçan kalplerinde uzun süreli ventriküler fibrilasyon modeli sunmaktadır. Bu model yüksek bir başarı oranına sahiptir, stabil, güvenilir ve tekrarlanabilir, kardiyak fonksiyon üzerinde düşük bir etkiye sahiptir ve sadece hafif miyokard hasarına neden olur.

İzole Sıçan Kalplerinde Uzun Süreli Ventriküler Fibrilasyon Modeli

Ventricular fibrillation (VF) is a fatal arrhythmia with a high incidence in cardiac patients, but VF arrest under perfusion is a neglected method of ...

Bu protokol, Langendorff aparatını kullanarak uzun süreli bir ventriküler fibrilasyon sıçan modeli geliştirmek için ayrıntılı bir ihtiyaç sağlar. Küçük hayvan modelinde uzun süreli ventriküler fibrilasyon boşluğunu doldurur. Teknik basit, ekonomik, tekrarlanabilir ve kararlıdır.Bu teknik, kalp cerrahisi seansları ve operasyonları alanında belirli klinik durumlarda gerçekleştirilen perfüzyon altında ventriküler fibrilasyon durması çalışmasında kullanılabilir. Başlamak için, Krebs-Henseleit veya KH tamponunu, damıtılmış suya 118 milimolar sodyum klorür, 4.7 milimolar potasyum klorür, 1.2 milimolar magnezyum klorür, 1.2 milimolar sodyum dihidrojen fosfat, 1.8 milimolar kalsiyum klorür, 25 milimolar sodyum bikarbonat, 11.1 milimolar glikoz ve 0.5 milimolar EDTA ekleyerek hazırlayın. Daha sonra modifiye Langendorff perfüzyon sistemini hazırlayın.KH tamponu içeren şişeyi yaklaşık 80 milimetre cıva basıncında %95 oksijen ve %5 karbondioksit ile sürekli olarak gazlayın. Perfüzyon tüpünün bir ucunu KH tamponuna yerleştirin, perfüzyon tüpünün ortasını su banyosundan geçirin ve perfüzyon tüpünün diğer ucuna künt bir 20 gauge iğne takın. İğneyi bir tel stand üzerinde askıya aldıktan sonra, su banyosunun sıcaklığını, perfüzyon sisteminin sonundan KH tamponunun sıcaklığı 37 santigrat derece olacak şekilde ayarlayın.Tüm analog sinyalleri dijitalleştirmek ve kaydetmek için fizyolojik bir sinyal kaydedici kullanın. Bipolar elektrokardiyogram veya EKG kaydetmek için iki paslanmaz çelik iğne elektrodu ve elektriksel stimülasyon için iki paslanmaz çelik iğne elektrodu kullanın. Dört elektrotun bir ucunu fizyolojik sinyal kaydediciye, diğer ucunu ise cihaza bağlandıktan sonra kalbin konumlandırılacağı alana yakın bir yere bağlayın.Ardından, bipolar EKG ve hemodinamik parametreleri otomatik olarak tanımak, ayarlamak ve kaydetmek için dizüstü bilgisayar yazılımını kullanın. Elektrik stimülatör parametrelerini, düşük voltaj grubu 2 volt ve yüksek voltaj grubu 6 volt alırken 30 hertz alternatif akıma ayarlayın. Servikal diseksiyon ve trakeal entübasyondan sonra ventilatöre bağlanan anestezili sıçan ile, cildi dişli forsepslerle ksifoid süreçten kaldırın ve doku makası ile deride üç santimetrelik enine bir kesi yapın.Deri ve kaburga insizyonlarını V şeklinde her iki taraftaki aksillaya uzatın. Brakiyosefalik gövdeyi çevreleyen dokudan ayırmak için künt diseksiyon kullanın. Daha sonra kalbin çıkarılmasını kolaylaştırmak için brakiyosefalik gövdeyi kavisli forsepslerle kelepçeleyin.Kalan kanı yıkamak ve pompalamak için kalbi derhal 0 ila 4 santigrat derecede KH tamponlu bir Petri kabına daldırın. Kalbi ikinci bir Petri kabına aktarın. Gereksiz dokuyu kesin ve aortu tanımlayın.Aortu kaldırmak ve aortu Langendorff aparatının künt iğnesine sokmak için iki oftalmik forseps kullanın. Sonra bir asistanın yardımıyla, 0 dikiş ipliği ile bir düğüm bağlayın. Perfüzyon akış regülatörünü açın.Balonu mitral kapaktan sol ventriküle doğru itin. 5 ila 10 milimetre cıva son diyastolik basıncı elde etmek için balonu damıtılmış suyla doldurun. EKG ve elektriksel stimülasyon elektrotlarını kalbe bağlayın.Kalbi, 37 santigrat derecede tutulan ceketli cam odanın ortasına yerleştirin. Kalbin odanın içinde 20 dakika boyunca dengelenmesine izin verin. Ardından, ceketli cam haznesindeki sıcaklığı 30 santigrat derecede tutmak için su banyosu sıcaklığını ayarlayın.Sıcaklık istenen seviyeye ulaştıktan sonra, dizüstü bilgisayar yazılımındaki elektriksel stimülasyon anahtarını etkinleştirin. Hayvan sürekli olarak uyarılan uzun süreli ventriküler fibrilasyon veya VF grubunun bir parçasıysa, 90 dakikalık elektriksel stimülasyona izin verin. 90 dakikalık VF'den sonra, 0.1 joule doğru akım defibrilasyonu vermek için elektrotlar kullanın.Aynı zamanda, ceketli cam oda içindeki sıcaklığın 10 dakika boyunca 37 santigrat dereceye yavaşça yükselmesini sağlamak için su banyosu sıcaklığını düzenleyin. Defibrilasyondan sonra, kalbin 60 dakika boyunca atmasına izin verin ve daha sonra yaklaşık 37 santigrat derecede% 10 potasyum klorür ile yavaş perfüzyonla atışı durdurun. Kreatin kinaz veya CK-MB testi ve histolojik analiz için kalbi çıkarın.Burada VF oranları, defibrilasyonun başarı oranı ve VF modelinin başarı oranı gösterilmektedir. Grup LC ve Grup HC sürekli elektriksel stimülasyon aldı ve böylece VF %100 başarı oranı ile gerçekleşti. Ancak grup HC, defibrilasyon için daha düşük başarı oranları göstermiştir.Elektriksel stimülasyonun beş dakika sonra kapatıldığı Grup LI ve Grup HI farklı VF oranlarına sahipti, ancak VF oranı her iki grupta da Grup LC ve Grup HC ile karşılaştırıldığında daha yavaştı. Hem Grup LC hem de Grup LI daha iyi defibrilasyon başarı oranlarına sahipti. Ancak genel olarak, Grup LC en yüksek model başarı oranına sahipken, Grup LI daha düşük bir model başarı oranına sahipti. Kalp hızı veya HR, koroner akım veya CF ve sol ventrikül basıncı farkı veya LVPD iyileşme oranları burada gösterilmektedir.Grup C'nin hemodinamiği deney sırasında stabil kaldı ve HR, CF ve LVPD'de hafif bir düşüş gösterdi. Düşük voltaj kaynaklı VF'ye sahip iki grup benzer performansa ve iyi bir iyileşme oranına sahipti. HR ve LVPD, bu gruplarda Grup C'ye kıyasla anlamlı olarak farklı değildi.Ancak KF'nin iyileşme oranı, Grup C.In kontrastına göre anlamlı derecede daha iyiydi, uzun süreli VF'ye indüklenen yüksek voltajlı iki grubun hemodinamik iyileşme oranı zayıftı ve yüksek voltajlı sürekli uyarılmış uzun süreli VF grubu en kötü iyileşme oranını gösterdi.Koroner efüzyon sıvılarının analizi, her iki yüksek voltaj grubunda da CK-MB düzeylerinin daha yüksek olduğunu göstermiştir. İki alçak gerilim grubu ile Grup C arasında fark saptanmadı.Hematoksilin ve eozin boyamasında Grup HC'de elektrot yanık bölgesi saptandı. Bu protokol kardiyovasküler cerrahide ventriküler fibrilasyon durması ve perfüzyon ile ilgili çalışmalar için uygundur.

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Research

JoVE Journal

Medicine

Assessment of Cardiac Function and Energetics in Isolated Mouse Hearts Using 31P NMR Spectroscopy

Bioengineered mouse models have become powerful research tools in determining causal relationships between molecular alterations and models of cardiovascular disease. Although molecular biology is necessary in identifying key changes in the signaling pathway, it is not a surrogate for functional significance. While physiology can provide answers to the question of function, combining physiology with biochemical assessment of metabolites in the intact, beating heart allows for a complete picture of cardiac function and energetics. For years, our laboratory has utilized isolated heart perfusions combined with nuclear magnetic resonance (NMR) spectroscopy to accomplish this task. Left ventricular function is assessed by Langendorff-mode isolated heart perfusions while cardiac energetics is measured by performing 31P magnetic resonance spectroscopy of the perfused hearts. With these techniques, indices of cardiac function in combination with levels of phosphocreatine and ATP can be measured simultaneously in beating hearts. Furthermore, these parameters can be monitored while physiologic or pathologic stressors are instituted. For example, ischemia/reperfusion or high workload challenge protocols can be adopted. The use of aortic banding or other models of cardiac pathology are apt as well. Regardless of the variants within the protocol, the functional and energetic significance of molecular modifications of transgenic mouse models can be adequately described, leading to new insights into the associated enzymatic and metabolic pathways. Therefore, 31P NMR spectroscopy in the isolated perfused heart is a valuable research technique in animal models of cardiovascular disease.

Assessment of Cardiac Function and Energetics in Isolated Mouse Hearts Using 31P NMR Spectroscopy

Langendorff-mode isolated heart perfusion, in conjunction with 31P NMR spectroscopy, combines the fields of biochemistry and physiology into one experiment. The protocol allows for the dynamic measurement of high energy phosphate content and turnover in the heart while concurrently monitoring physiologic function. When performed correctly, this is a valuable technique in the assessment of cardiac energetics.

Kalp Fonksiyonu ve Enerji Kullanımı İzole Fare Kalpler Değerlendirilmesi 31 P NMR Spektroskopisi

Bioengineered mouse models have become powerful research tools in determining causal relationships between molecular alterations and models of ...

Tıp

NADH Fluorescence Imaging of Isolated Biventricular Working Rabbit Hearts

Since its inception by Langendorff1, the isolated perfused heart remains a prominent tool for studying cardiac physiology2. However, it is not well-suited for studies of cardiac metabolism, which require the heart to perform work within the context of physiologic preload and afterload pressures. Neely introduced modifications to the Langendorff technique to establish appropriate left ventricular (LV) preload and afterload pressures3. The model is known as the isolated LV working heart model and has been used extensively to study LV performance and metabolism4-6. This model, however, does not provide a properly loaded right ventricle (RV). Demmy et al. first reported a biventricular model as a modification of the LV working heart model7, 8. They found that stroke volume, cardiac output, and pressure development improved in hearts converted from working LV mode to biventricular working mode8. A properly loaded RV also diminishes abnormal pressure gradients across the septum to improve septal function. Biventricular working hearts have been shown to maintain aortic output, pulmonary flow, mean aortic pressure, heart rate, and myocardial ATP levels for up to 3 hours8.
When studying the metabolic effects of myocardial injury, such as ischemia, it is often necessary to identify the location of the affected tissue. This can be done by imaging the fluorescence of NADH (the reduced form of nicotinamide adenine dinucleotide)9-11, a coenzyme found in large quantities in the mitochondria. NADH fluorescence (fNADH) displays a near linearly inverse relationship with local oxygen concentration12 and provides a measure of mitochondrial redox state13. fNADH imaging during hypoxic and ischemic conditions has been used as a dye-free method to identify hypoxic regions14, 15 and to monitor the progression of hypoxic conditions over time10.
The objective of the method is to monitor the mitochondrial redox state of biventricular working hearts during protocols that alter the rate of myocyte metabolism or induce hypoxia or create a combination of the two. Hearts from New Zealand white rabbits were connected to a biventricular working heart system (Hugo Sachs Elektronik) and perfused with modified Krebs-Henseleit solution16 at 37 &deg;C. Aortic, LV, pulmonary artery, and left &amp; right atrial pressures were recorded. Electrical activity was measured using a monophasic action potential electrode. To image fNADH, light from a mercury lamp was filtered (350&plusmn;25 nm) and used to illuminate the epicardium. Emitted light was filtered (460&plusmn;20 nm) and imaged using a CCD camera. Changes in the epicardial fNADH of biventricular working hearts during different pacing rates are presented. The combination of the heart model and fNADH imaging provides a new and valuable experimental tool for studying acute cardiac pathologies within the context of realistic physiological conditions.

The objective is to monitor the mitochondrial redox state of isolated hearts within the context of physiologic preload and afterload pressures. A biventricular working rabbit heart model is presented. High spatiotemporal resolution fluorescence imaging of NADH is used to monitor the mitochondrial redox state of epicardial tissue.

İzole Biventriküler ve NADH Floresans Görüntüleme Tavşan Kalpler Çalışma

Since its inception by Langendorff1, the isolated perfused heart remains a prominent tool for studying cardiac physiology2. However, it is not well-suited ...

Reduction in Left Ventricular Wall Stress and Improvement in Function in Failing Hearts using Algisyl-LVR

Injection of Algisyl-LVR, a treatment under clinical development, is intended to treat patients with dilated cardiomyopathy. This treatment was recently used for the first time in patients who had symptomatic heart failure. In all patients, cardiac function of the left ventricle (LV) improved significantly, as manifested by consistent reduction of the LV volume and wall stress. Here we describe this novel treatment procedure and the methods used to quantify its effects on LV wall stress and function.
Algisyl-LVR is a biopolymer gel consisting of Na+-Alginate and Ca2+-Alginate. The treatment procedure was carried out by mixing these two components and then combining them into one syringe for intramyocardial injections. This mixture was injected at 10 to 19 locations mid-way between the base and apex of the LV free wall in patients.
Magnetic resonance imaging (MRI), together with mathematical modeling, was used to quantify the effects of this treatment in patients before treatment and at various time points during recovery. The epicardial and endocardial surfaces were first digitized from the MR images to reconstruct the LV geometry at end-systole and at end-diastole. Left ventricular cavity volumes were then measured from these reconstructed surfaces.
Mathematical models of the LV were created from these MRI-reconstructed surfaces to calculate regional myofiber stress. Each LV model was constructed so that 1) it deforms according to a previously validated stress-strain relationship of the myocardium, and 2) the predicted LV cavity volume from these models matches the corresponding MRI-measured volume at end-diastole and end-systole. Diastolic filling was simulated by loading the LV endocardial surface with a prescribed end-diastolic pressure. Systolic contraction was simulated by concurrently loading the endocardial surface with a prescribed end-systolic pressure and adding active contraction in the myofiber direction. Regional myofiber stress at end-diastole and end-systole was computed from the deformed LV based on the stress-strain relationship.

This article describes procedures for implanting a novel hydrogel in failing hearts and quantifying its effect on left ventricular wall stress and function. These procedures have been successfully applied in dogs and humans.

Algisyl-LVR kullanarak Hearts başarısız Fonksiyon Sol Ventrikül Duvar Stres ve İyileştirme azalma

Injection of  Algisyl-LVR, a treatment under clinical development, is intended to treat  patients with dilated cardiomyopathy. This treatment was recently ...

Method of Isolated Ex Vivo Lung Perfusion in a Rat Model: Lessons Learned from Developing a Rat EVLP Program

The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and &#8220;pearls of wisdom&#8221;/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible.

Method of Isolated Ex Vivo Lung Perfusion in a Rat Model: Lessons Learned from Developing a Rat EVLP Program

Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. Here, we describe the development of a rat EVLP program and refinements that allow for a reproducible model for future expansion.

İzole Yöntemi<em&gt; Ex vivo</emBir Rat Modelinde&gt; Akciğer Perfüzyon: Sıçan EVLP Programı Geliştirme Öğrenilmiş Dersler

The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed ...

A Rat Model of Ventricular Fibrillation and Resuscitation by Conventional Closed-chest Technique

A rat model of electrically-induced ventricular fibrillation followed by cardiac resuscitation using a closed chest technique that incorporates the basic components of cardiopulmonary resuscitation in humans is herein described. The model was developed in 1988 and has been used in approximately 70 peer-reviewed publications examining a myriad of resuscitation aspects including its physiology and pathophysiology, determinants of resuscitability, pharmacologic interventions, and even the effects of cell therapies. The model featured in this presentation includes: (1) vascular catheterization to measure aortic and right atrial pressures, to measure cardiac output by thermodilution, and to electrically induce ventricular fibrillation; and (2) tracheal intubation for positive pressure ventilation with oxygen enriched gas and assessment of the end-tidal CO2. A typical sequence of intervention entails: (1) electrical induction of ventricular fibrillation, (2) chest compression using a mechanical piston device concomitantly with positive pressure ventilation delivering oxygen-enriched gas, (3) electrical shocks to terminate ventricular fibrillation and reestablish cardiac activity, (4) assessment of post-resuscitation hemodynamic and metabolic function, and (5) assessment of survival and recovery of organ function. A robust inventory of measurements is available that includes &#8211; but is not limited to &#8211; hemodynamic, metabolic, and tissue measurements. The model has been highly effective in developing new resuscitation concepts and examining novel therapeutic interventions before their testing in larger and translationally more relevant animal models of cardiac arrest and resuscitation.

This article describes a rat model of electrically-induced ventricular fibrillation and resuscitation by chest compression, ventilation, and delivery of electrical shocks that simulates an episode of sudden cardiac arrest and conventional cardiopulmonary resuscitation. The model enables gathering insights on the pathophysiology of cardiac arrest and exploration of new resuscitation strategies.

Konvansiyonel Kapalı göğüs Tekniği ile Rat Ventriküler Fibrilasyon Modeli ve Resüsitasyon

A rat model of electrically-induced ventricular fibrillation followed by cardiac resuscitation using a closed chest technique that incorporates the basic ...

Induction and Assessment of Ischemia-reperfusion Injury in Langendorff-perfused Rat Hearts

The biochemical events surrounding ischemia reperfusion injury in the acute setting are of great importance to furthering novel treatment options for myocardial infarction and cardiac complications of thoracic surgery. The ability of certain drugs to precondition the myocardium against ischemia reperfusion injury has led to multiple clinical trials, with little success. The isolated heart model allows acute observation of the functional effects of ischemia reperfusion injury in real time, including the effects of various pharmacological interventions administered at any time-point before or within the ischemia-reperfusion injury window. Since brief periods of ischemia can precondition the heart against ischemic injury, in situ aortic cannulation is performed to allow for functional assessment of non-preconditioned myocardium. A saline filled balloon is placed into the left ventricle to allow for real-time measurement of pressure generation. Ischemic injury is simulated by the cessation of perfusion buffer flow, followed by reperfusion. The duration of both ischemia and reperfusion can be modulated to examine biochemical events at any given time-point. Although the Langendorff isolated heart model does not allow for the consideration of systemic events affecting ischemia and reperfusion, it is an excellent model for the examination of acute functional and biochemical events within the window of ischemia reperfusion injury as well as the effect of pharmacological intervention on cardiac pre- and postconditioning. The goal of this protocol is to demonstrate how to perform in situ aortic cannulation and heart excision followed by ischemia/reperfusion injury in the Langendorff model.

The isolated rat heart is an enduring model for ischemia reperfusion injury. Here, we describe the process of harvesting the beating heart from a rat via in situ aortic cannulation, Langendorff perfusion of the heart, simulated ischemia-reperfusion injury, and infarct staining to confirm the extent of ischemic insult.

Langendorff-perfüze sıçan Hearts indüksiyon ve İskemi-reperfüzyon Hasarı Değerlendirilmesi

The biochemical events surrounding ischemia reperfusion injury in the acute setting are of great importance to furthering novel treatment options for ...

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early cardiopulmonary dysfunction is difficult to diagnose, particularly in animal models, as cardiopulmonary function is often measured invasively, requiring anesthesia. As many anesthetic agents are cardiodepressive, subtle changes in cardiovascular function may be masked. In contrast, chronic instrumentation allows for measurement of cardiopulmonary function in the awake state, so that measurements can be obtained under quiet resting conditions, without the effects of anesthesia and acute surgical trauma. Furthermore, when animals are properly trained, measurements can also be obtained during graded treadmill exercise.
Flow probes are placed around the aorta or pulmonary artery for measurement of cardiac output and around the left anterior descending coronary artery for measurement of coronary blood flow. Fluid-filled catheters are implanted in the aorta, pulmonary artery, left atrium, left ventricle and right ventricle for pressure measurement and blood sampling. In addition, a 20 G&#160;catheter is positioned in the anterior interventricular vein to allow coronary venous blood sampling.
After a week of recovery, swine are placed on a motor-driven treadmill, the catheters are connected to pressure and flow meters, and swine are subjected to a five-stage progressive exercise protocol, with each stage lasting 3 min. Hemodynamic signals are continuously recorded and blood samples are taken during the last 30 sec of each exercise stage.
The major advantage of studying chronically instrumented animals is that it allows serial assessment of cardiopulmonary function, not only at rest but also during physical stress such as exercise. Moreover, cardiopulmonary function can be assessed repeatedly during disease development and during chronic treatment, thereby increasing statistical power and hence limiting the number of animals required for a study.

Here we present a protocol to assess cardiopulmonary function in awake swine, at rest and during graded treadmill exercise. Chronic instrumentation allows for repeated hemodynamic measurements uninfluenced by cardiodepressive anesthetic agents.

Domuz uzun süreli Kardiyovasküler Egzersiz Testi için Kateter Cerrahi Yerleştirme

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early ...

Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. Indeed, research focusing on the discovery of new potential therapeutic targets using genetically altered mice requires a reliable, long-term assessment of the systemic arterial pressure variation. Currently, the gold standard for obtaining long-term measurements of blood pressure in ambulatory mice uses implantable radio-transmitters, which require&#160;artery cannulation. This technique eliminates the need for tethering, restraining, or anesthetizing the animals which introduce stress and artifacts during data sampling. However, arterial blood pressure monitoring in mice via catheterization can be rather challenging due to the small size of the arteries. Here we present a step-by-step guide to illustrate the crucial key passages for a successful subcutaneous implantation of radio-transmitters and carotid artery cannulation in mice. We also include examples of long-term blood pressure activity taken from freely moving mice after a period of post-surgery recovery. Following this procedure will allow reliable direct blood pressure recordings from multiple animals simultaneously.

The goal of this protocol is to assess systemic blood pressure in conscious freely moving mice using implantable radio-telemetry devices.

Telemetri kullanarak Serbestçe Hareketli Fare Uzun süreli Tansiyon Ölçümü

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. ...

The Inverted Heart Model for Interstitial Transudate Collection from the Isolated Rat Heart

The present protocol describes a unique approach that enables the collection of cardiac transudate (CT) from the isolated, saline-perfused rat heart. After isolation and retrograde perfusion of the heart according to the Langendorff technique, the heart is inverted into an upside-down position and is mechanically stabilized by a balloon catheter inserted into the left ventricle. Then, a thin latex cap &#8211; previously cast to match the average size of the rat heart &#8211; is placed over the epicardial surface. The outlet of the latex cap is connected to silicon tubing, with the distal opening 10 cm below the base level of the heart, creating slight suction. CT continuously produced on the epicardial surface is collected in ice-cooled vials for further analysis. The rate of CT formation ranged from 17 to 147 &#181;L/min (n = 14) in control and infarcted hearts, which represents 0.1-1% of the coronary venous effluent perfusate. Proteomic analysis and high performance liquid chromatography (HPLC) revealed that the collected CT contains a wide spectrum of proteins and purinergic metabolites.

This protocol describes a method to collect cardiac interstitial fluid from the isolated, perfused rat heart. To physically separate interstitial transudate from coronary venous effluent perfusate, the Langendorff perfused heart is inverted, and the transudate (interstitial fluid) formed on the cardiac surface is collected using a soft latex cap.

İzole edilen fare kalpten interstisyel transüdao toplanması için ters kalp modeli

The present protocol describes a unique approach that enables the collection of cardiac transudate (CT) from the isolated, saline-perfused rat heart. ...

Standardized Model of Ventricular Fibrillation and Advanced Cardiac Life Support in Swine

Cardiopulmonary resuscitation after cardiac arrest, independent of its origin, is a regularly encountered medical emergency in hospitals as well as preclinical settings. Prospective randomized trials in human subjects are difficult to design and ethically ambiguous, which results in a lack of evidence-based therapies. The model presented in this report represents one of the most common causes of cardiac arrests, ventricular fibrillation, in a standardized setting in a large animal model. This allows for reproducible observations and various therapeutic interventions under clinically accurate conditions, hence facilitating the generation of better evidence and eventually the potential for improved medical treatment.

Cardiopulmonary resuscitation and defibrillation are the only effective therapeutic options during cardiac arrest caused by ventricular fibrillation. This model presents a standardized regimen to induce, assess, and treat this physiological state in a porcine model, thus providing a clinical approach with various opportunities for data collection and analysis.

Domuzda Standart Ventriküler Fibrilasyon Ve İleri Kardiyak Yaşam Desteği Modeli

Cardiopulmonary resuscitation after cardiac arrest, independent of its origin, is a regularly encountered medical emergency in hospitals as well as ...